Invasive Stink Bugs and Related Species (Pentatomoidea)

Nezara viridula ( L .) 377

7.4.4.4 Diapause Maintenance in the Laboratory

When adults enter winter diapause under constant short-day conditions in the laboratory, they
remain dormant (i.e., dark-colored and mostly motionless) for varying periods of time before their
diapause is terminated spontaneously. Adults that experience shorter day-lengths exhibit russet col-
oration for longer periods (Figures 7.7 and 7.12). For example, at 25°C, the median period during
which females exhibited stable russet body coloration varied considerably depending on photo-
period (i.e., 84 days under L:D 13:11, 126 days under L:D 12:12, and 154 days under L:D 10:14;
Figure 7.12; Musolin et al. 2007).

30

20

10

50

40

30

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0

50

40

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0

0

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L:D 10:14

A Diapause

induction stage

B Diapause maintenance

and termination stages

L:D 12:12

L:D 13:11

Days after adult emergence

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40

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20

10

0

20

10

0

0306060 090 120 150 180 210 240 270 300 330 360

0

Numb

er of female

s

30 60 60 90 120 150 180 210 240 270 300 330 360

030606090 120 150 180 210 240 270 300 330 360

FIGURE 7.12 Effect of day length on body color change and diapause induction (A) and diapause maintenance and
termination (B) in female Nezara viridula at 25°C under laboratory conditions. On day 60 after adult emergence, green
and intermediately colored individuals were removed and only russet ones were left for further exposure (B). Histograms
denote survival and relative abundance of color grades: white bars, green; gray bars, intermediate; and black bars, russet.
The dotted line and solid line overlaid on the histograms denote cumulative copulation and cumulative oviposition, respec-
tively. (From D. L. Musolin, K. Fujisaki, and H. Numata, Physiological Entomology 32: 64–72, 2007, with permission.)